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Nuclear energy is clean

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Re: Nuclear energy is clean

#671

Post by pfdietz »

panick21_ wrote: post #593
Flocular wrote: post #46

A good estimate to gauge the societal investment needed to generate electricity in a certain way, is to look at its total cost in dollar/MWh. Wikipedia has a nice graphic prepared for just that: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#... (which ignores externalized costs like CO2 or nuclear waste) You can see in there that nuclear has triple the cost compared to solar. As we need to replace as mu…

What is more interesting to me is asking the question based on first principles. If you consider the global electricity and energy demand and wanted to meet it, what you produce the least amount of green house gases, use the least amount of land, require the least amount of mining. If you actually do that nuclear wins easily witch suggest there is some other process at work that makes sure this is not translated into…

Why would you want to use the least amount of land, or do the least amount of mining?

Re: Nuclear energy is clean

#672

Post by TheSpiceIsLife »

cycomanic wrote: post #289

This article perfectly exemplifies the arguments in discussions. Lets just concentrate on the waste discussion. The article says heavy metals in solar panels are a problem (I kind of agree, although the way it is described makes it out like we are talking about huge amounts, in reality the lead in solar panels is largely from soldering so very small amounts. Orders of magnitude more are being used for other applicati…

I just don't understand why otherwise intelligent people cannot grasp that long lived nuclear waste also means it isn't very radioactive at all.

Re: Nuclear energy is clean

#673

Post by Krasnol »

bilekas wrote: post #660
Krasnol wrote: post #657

Earlier quoted context omitted.

Are you trolling me? I didn't say this is supposed to be the only way of getting power. You can put solar everywhere. Not just on roofs and you might have heard about wind. That's a thing too.

Don't take it as a slight. - We're only discussing here > I didn't say this is supposed to be the only way of getting power. Your previous comments do sign you up very much in favour of anything other than nuclear. > . Not just on roofs and you might have heard about wind. That's a thing too. It certainly is, but to my previous point of 'per square meter return' .. Are you planning to organise a turbine with the loca…

> Renewable's are amazing, the more the merrier. But discarding nuclear over it's waste isn't a genuine argument.

How isn't it when it actually is in Germany?

> We've gotten better than the 60s/70/80 when old plants were built

How so when the waste from those reactors is still stored next to those reactors?

> That shouldn't stop us from pursuing cheap energy.

Nuclear is not cheap.

> We also know how to use solar, wind and aqua. It will never be as efficient as splitting the atom though.

It doesn't have to be as "efficient" as your steam engine with generations-waste-extra. It's cheap as hell and it's getting cheaper and better fast. Something you can't say about nuclear. A technology from the past.

> Again I reiterate - Why not both ?

Because:

a) you didn't offer any solution for the waste

b) you can spend every dollar only once

c) we're right on the path to the new cold war....you should get rid of those rotting vulnerabilities and opt in for decentralised independence.

Re: Nuclear energy is clean

#674

Post by yellowapple »

ncmncm wrote: post #454
yellowapple wrote: post #234

Earlier quoted context omitted.

Nuclear is already more than competitive. The appearance otherwise is overwhelmingly artificial.

When your argument depends on promoting falsehoods, one wonders why you bother.

I, too, wonder why people uncritically parrot the fossil fuel industry's anti-nuclear talking points without even having the decency to be paid for it.

Re: Nuclear energy is clean

#675

Post by onethought »

JacobiX wrote: post #571
blackoil wrote: post #428

Earlier quoted context omitted.

Not sure how much Europe would like to be dependent on Russia, Libya, Turkey ... for the energy requirements.

As I understand from reading Vaclav Smil's “How the World Really Works”. Replacing fossil fuels by renewables isn't simple: "we are a fossil-fueled civilization whose technical and scientific advances, quality of life, and prosperity rest on the combustion of huge quantities of fossil carbon, and we cannot simply walk away from this critical determinant of our fortunes in a few decades, never mind years."

Of course we can. Just do the calculation into TW and then that’s how much renewables we need. We built a ridiculous world war machine in less than 10 years and then a crazy space machine in the 20 years after that. Making wind and solar is kind of easy and as you did it it would get cheaper to do (as you lowered the cost of energy to 0)

Re: Nuclear energy is clean

#676

Post by onethought »

ETH_start wrote: post #605
ncmncm wrote: post #499

Earlier quoted context omitted.

Nukes also involve big transmission line projects, so it is a wash,.

Not nearly as much as requires to overcome the intermittency issue of renewable power sources.

To completely replace fossil fuel, you need a lot of nuclear plants and nuclear materials and transmission lines. For renewables you can handle a lot of the load near the consumption point and only need to transmit the “night load” which is usually much less.

Re: Nuclear energy is clean

#677

Post by onethought »

not_a_pet_rock wrote: post #390
onethought wrote: post #358

Earlier quoted context omitted.

Why aren’t they base load? If every country over provisioned renewables, then you have a transmission problem not a storage problem. The sun does always shine, the wind does always blow.

wind does not always blow nor can you always deploy a turbine and you clearly don't understand the ridiculous amount of space taken by the windmills to actually over provision. Technically if you were to over provision, yes that would work, but the problem is more that you cant even do it because of multiple different reasons. It's easier to understand when you realize that we don't have more hydro because most of th…

Australia + Saudi Arabia + Utah each have enough empty land to easily provision the worlds energy requirements in solar alone. The sun is always shining on at least one of them (maybe the pacific is a bit too big, but we are talking only a couple of hours).

Denmark is not the only place the wind blows in the world. There are many windy places globally.

But I agree nuclear is another option, but it’s not the only way

Re: Nuclear energy is clean

#678

Post by panick21_ »

I_am_tiberius wrote: post #643
panick21_ wrote: post #595

Earlier quoted context omitted.

> terror attack doesn't cause a 1000 km2 area around the plant to be unlivable for 100 years That can't actually happen. And if you believe it can, you are wrong. Please explain the mechanics of how that would happen to me! Ill wait.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1122278/

I can't actually find what mock terrorist attack these were and what effects there were.

Sure in theory enough radio active materials exists that if you somehow blew it up and vaporized the whole spend fuel pool it would require a significant exclusion zone. To put such amount of explosives into that pool to vaporize the spent fuel roads would require an absurd amount of explosives.

And the exclusion zone for these things is way to big anyway, many people live in the Chernobyl exclusion zone and they are not actually negatively impacted.

But of course if you assume terrorist of unlimited capabilities there lots of technologies that are not viable and we use them anyway.

Re: Nuclear energy is clean

#679

Post by credit_guy »

pfdietz wrote: post #668
credit_guy wrote: post #640

Earlier quoted context omitted.

I read this opinion in that blog of Austin Vernon that made the HN rounds about a year ago [1]. In the end his argument is basically "if some energy generation method has moving parts, it has to be more expensive that one that doesn't". But let's look at the numbers. Here's a study by the EIA that looks at the capital costs and also at the Operating and Maintenance costs of various types of power plants [2]. The cost…

Gas is cheap because it substantially reduces the number of heat exchangers. Transferring heat across a solid/fluid interface is kind of expensive. The more of that you have to do, the more expensive your power plant will be. A simple cycle combustion turbine involves no heat exchangers at all. Heat is generated in the compressed air by combustion; the waste heat is carried away in the air + combustion products exiti…

That's the idea behind the gas-cooled fast reactor [1]:

  The reference reactor design is a helium-cooled system operating with an outlet temperature of 850 °C using a direct Brayton closed-cycle gas turbine for high thermal efficiency.
Helium does not absorb neutrons when it passes through the core, and if the nuclear fuel is well insulated (such as the TRISO fuel that Xe-100 plans to use), then you are safe to send it to spin the turbine. If you have any concerns that the cooling gas may become contaminated somehow, then you use a heat-exchanger.

At this point nobody is using direct cooling-gas-to-turbine cycle. But after people gain experience with cooling-gas-to-heat-exchanger, at some point they'll move to the direct cycle.

[1] https://en.wikipedia.org/wiki/Gas-cooled_fast_reactor

[2] https://en.wikipedia.org/wiki/Nuclear_fuel#TRISO_fuel

Re: Nuclear energy is clean

#680

Post by pfdietz »

credit_guy wrote: post #679
pfdietz wrote: post #668

Earlier quoted context omitted.

Gas is cheap because it substantially reduces the number of heat exchangers. Transferring heat across a solid/fluid interface is kind of expensive. The more of that you have to do, the more expensive your power plant will be. A simple cycle combustion turbine involves no heat exchangers at all. Heat is generated in the compressed air by combustion; the waste heat is carried away in the air + combustion products exiti…

That's the idea behind the gas-cooled fast reactor [1]: The reference reactor design is a helium-cooled system operating with an outlet temperature of 850 °C using a direct Brayton closed-cycle gas turbine for high thermal efficiency. Helium does not absorb neutrons when it passes through the core, and if the nuclear fuel is well insulated (such as the TRISO fuel that Xe-100 plans to use), then you are safe to send i…

A problem with these reactors using TRISO fuel is it greatly increases the volume of waste. The spent fuel is now mixed with a large amount of carbon. Cask storage becomes less practical.

Also, any time the temperature is above 550 C you can't use ordinary steels, as they will creep. So these reactors have materials challenges.

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